A Mechanic's Life - Tales From Under the Hood

Comments

Hell, I use an old-school bubble balancer at home. I've mounted and balanced at least 20 sets ranging from 14" to 18" in the past few years this way without a problem. Its just what I'm used to. Its the same balancer I used back when I was 7 years old working in my dad's shop.

Most places around here do the mount/balance for about $60. The local Ford dealership charges $90 for theirs, but they also use the Hunter RF9700. What I find is that not only are the tires better balanced (although I've never had an out-of-balance that was noticeable at under 70 mph, which is where 99% of my driving occurs), but the amount of weight used to balance them seems to be considerably less. Of course, that's on the same rims, but with different tires, so the tires themselves could be the difference?

I'm not sure why, but for some reason that just seems worth an extra $30 to me.

The only thing that bugs me is that there isn't a differential rate for mounted vs. unmounted wheels (meaning on or off a vehicle). It seems to me that changing tires on rims that are mounted on a vehicle should take more time and effort than ones that are not... yet the price is the same. :confuse:

You would add yourself to bearcats list of people who couldn't balance his tires with that.

Probably. Sounds like his wheels and/or tires are really messed up. Luckily, all the ones I have done haven't had that problem. I even balanced out the set that the BMW dealership told me was bent. Still running them now.

I had tires balanced for years with the old bubble balancers, and, never had problems. My son has one. If he didn't live 200 miles from me, I'd took the Honda to him. Bet he'd done a better job than the chain tire store did. The Mercedes dealer here uses a road force balancer and gets 'em perfect. A couple of years ago, I needed tires for an 06 Jaguar, and had them pick up the tires from the tire store and mount and balance them. Yeah, it cost me a bit more - but - they actually found that two of the new tires were out of specification with the road force balancer, and, made the tire dealer replace them. Now a story about some of the crap I've run into. A few years ago, I went to a big national retailer and bought a set of tires for a 95 Chrysler LHS. I got the car back, and, headed home, which involved a 10 mile interstate run. As soon as I got on the interstate, I had violent wheel shake, so I went back to their auto center for a re-balance. From their waiting room, I was watching their guy work on my car. He didn't even put it on a lift or take the wheels off. As I watched, he took a tire pressure guage and let air out of all 4 tires. a few minutes later, they told me my car was all fixed. I went out, got my tire pressure guage out, and verified that I now had 25 psi in all 4 tires. I went back in, grabbed a store manager, and showed him what they did. Then I made him refund all the balancing charges, and, I went to another shop and had them balance the wheels correctly.

I was given a repair order for a complaint of wheel/tire vibration. We used a bubble balancer back then and we would use four weights which had us putting the weights at a 60 degree angle on each side of the wheel. I could then slide the weights towards each other a little to make them "heavier" if I needed a little more weight or if I had a little too much I could slide them apart from each other to make them "lighter". Back in those days, this was easily "good enough". I road tested the car and it was fine. The next day the guy was back and it was vibrating like crazy again. I put the first tire on the balancer and it was off by about three ounces! I rebalanced the tire, but there was no way that I had missed by that much, something was going on here. I picked the tire up off of the balancer, and bounced it. and then put it back on. It was again off by three ounces.

This guy had been using so much stop leak in his tires that it was like a ball of wet newspaper inside the tire, in fact all four of them were like that.

I had to take the tires apart, clean all of that trash out of the tires, replaced the bad valve stems, cleaned the rust from wheel beads, and patched one of the tires and rebalanced them. I didn't get paid a cent for all of that because "it was a comeback".

they do charge more to take the tires off the car. I can get tires mounted and balanced for $10, including tire disposal. And, they're open, not 24 7 but almost all the time. National chain. I wouldn't let them touch anything on my car though.

Interesting turn of discussion. My 03 Grand Marquis has a hard to fix slight back and forth wobble, and the Marauder guys say it's common, and needs road force balanced, with hot tires.

I would assess that to be bad belts in a tire or bent rim. Out of round tires give more of an up and down movement.

Road force balancers can ameliorate out-of-roundness due to differences in compression of the tire at different parts of its circumference. The tech measures the rim for its high point and then places the high part of the tire at the low part of the rim hoping they will reduce the effective out-of-roundness. If a tire or rim is out a lot, then the tech can move the tire to another rim which has more variation if available. After reducing out-of-roundness as much as possible, then the balancer spins the tire for dynamic balancing: they do not correct for out-of-roundness due to compression variation in the spin balancing.

I've changed rims tires all tie rod ends lower bjs and upper control arms. I know that drives some folks crazy But boy, is the front end tighter, and each thing made the wobble a little smaller. Should've done the lower control arms and struts too while I was there, but it's all about the money. Looking forward to upgrading the struts.

After much wailing and gnashing of teeth I found out that the 03+ panthers can have this problem. They are extremely sensitive to their balancing for some reason. I'll report back when I have the road force done.

But what kills me (and comes back to this thread somewhat) is blankityblank reliability! Simplicity. My old cars might not handle as 'well', but I could balance the tires and drive away.

A guy over in another topic has an Audi that eats the *inside* of his front tires every 10,000 miles. He insists that the suspension has been checked over, the car's been on a frame machine, and that there is no suspension problem. My contention was that it HAS to be a suspension problem (camber). Both tires wear pretty much equally on their insides, except he says that the driver's side a bit more perhaps.

ideas? What besides a suspension problem could cause what seems to be symptomatic of excessive camber?

On another interesting note...two nitro funny car owners differed when it came to balancing their tires which run up to 300 mph. John Force had a high speed balancer. Next to him was the Hawaiian Punch funny car. A quick peek revealed...guess what....a bubble balancer.

While I believe in the quality of snap on tools. Their low speed (hand crank) balancer leaves much to be desired. While I have successfully balanced tires using the Snap on balancer at times the results were inconsistent. In other words customers have returned with vibrations that they didn't have prior to coming to the shop.

I understand the $10K price difference and it appears you don't specialize in tires making the Hunter 9700 difficult to justify. I'm just wondering if there are better balancers out there for the $4K paid for Snap on's version.

He also says that Audi assured him a number of times that the car is completely within spec.

Just getting it "in the green" isn't always good enough. Today's alignment machines produce a print out of the specs, and the current settings. I need to see the specs. Today many cars don't come with full adjustment capability, and it comes down to aftermarket solutions to make full adjustments.

While I believe in the quality of snap on tools. Their low speed (hand crank) balancer leaves much to be desired.

With wheels that mount up correctly it's "fine" mode allows me to balance the assembly dynamically to within two grams.

The problem comes down to wheel designs that just refuse to cleanly mount with the available centering cones. The balance, then reposition and recheck routine catches the problem wheels all the time. The trick then is to be patient and see if a solution can be arrived at, one wheel at a time.

As far as justifying a $14,000 balancer, I can't really justify owning the $4000 one, I'm a driveability/electronics/repair shop and have no employee's. I wouldn't sell enough tires in a month to even make enough gross profit to cover the payment on a new balancer.

This was a first time customer who was referred to us. He's been dealing with a repeated check engine light for more than a year and it always came up with the code description for a large evaporative emissions leak. It's had no less than three gas caps put on it, several smoke tests, the canister vent valve has been replaced and every time the light simply came right back on in a couple of days.

When diagnosing any evap failure, the first step is to understand the particular system that is on the car you need to diagnose, and how the car's computer tests the system. Then you can start testing the system just like the computer on the car does.

From "an instructors" point of view the pull a code and guess a part approach fails the moment that no effort is put into trying to understand how the system works. For this customer, three parts stores pulled the code and all three sold him a gas cap. On a second visit to one of them he was sold the canister vent valve.

He went to several shops requesting a smoke test of the system. A smoke test uses a pressurized system to pump smoke into the fuel tank and the carbon cannister and it's hoses and lines. If the system has a leak, the smoke shows where it's at. (most of the time) The smoke tests could not locate a leak.

He came to my shop requesting a smoke test, I told him a better approach would be to simply allow us to diagnose the problem, and I would use my smoke machine as part of that process if necessary.

He agreed to that approach.

As I mentioned, the first step is to be sure that you understand the system. The second step of the diagnostics is to attach a scan tool, retrieve the code and begin the process of testing the system. You must do this while forgetting everything else that you have been told has been checked/replaced/tested. (Any ideas why I mentioned that right here?)

What is the next step and why?

How would you proceed with testing this system to repair the problem?

BTW, it was really refreshing to have this customer be appreciative for us solving this problem for him.